Improvement in spirally-wound sheet-metal tubes



H. NOBLE.

SPIRALLY-WOUND SHEET-METAL TUBE.

Patented June 19,1877,

UNITED STATES- PATENT OFFICE.

HENRY NOBLE, or BOSTON, MASSACHUSETTS.

IMPROVEMENT IN SPlRALLV-WOUND SHEET-METAL TUBES.

Specification forming part of Letters Patent No. 192,079, dated June 19,1877; application filed December 4, 1876,

To all whom it may concern:

Be it known that I, HENRY NOBLE, of Bos ton, in the county of Suffolkand State of Mas-- sachusetts, have invented certain Improvements inspirally-Wound Sheet-Metal Pipes or Tubes, ofwhich the following is afull, clear, and exact description, reference being had to theaccompanying drawings, making part of this specification, in which-Figure l is a perspective view of a spirally- Wound sheet-metal pipeconstructed in accordance with my invention. Fig. 2 is a perspectiveview, representing the mannerin which the pipe is formed. Fig. 3 is atransverse section representing the seam or joint finished. Fig. 1 is asection (enlarged) representing the seam or joint previous to its beingflattened down or finished. Fig. 5 represents the strip of sheet metalof the desired width from which myimproved pipeis formed. Fig. 6represents the narrow strip of sheet metal employed in re-eniorcing theseam of the said pipe.

My invention relates to that class of sheetmetal pipes which are formedby winding the strip spirally around a mandrel; and my inventionconsists in uniting the edges of the strip, and re-eni'orcing the seamor joint so formed by means of a separate and i Independent strip ofn1etal clinched down on the outside of the same, in such a manner as tohold the edges of the strip firmly together, the liability of theseparation of the edges and the loosening and opening of thejointincident to this class of pipes, as heretofore constructed,

being thereby avoided.

To enable others skilled in the art to understand and use my invention,1 will proceed to describe the manner in which I have carried it out.

In the said drawings, A represents a flat strip of sheet metal, of therequired width, and a a narrow strip of metal, both of which, as theyare fed through a machine adapted for the purpose, are wound spirallyaround a mandrel or former, during which operation the edges ofthest'rip' A are turned .up, and the edges of the strip a turned down,as seen in Fig.2, by suitable mechanism, after which the turned edges ofthe strip a, Fig. 6,

are directed against and caught over the turned edges of the strip A,simultaneously with their being made to abut against each other, theparts being then in the position seen in Fig. 4.

roll or other device, the inside of the joint be- 'ing at the same timesmoothly finished, so as to offer no obstruction.

The above-described joint imparts stiffness and rigidity to the pipe,(which can conse 'quently be made of thinner metal than heretofore,) forthe reason that the edges abut squarely against each other, and are heldfirmly and immovably together by the re-enforcing-strip 00, whereas thisclass of pipe, when provided with a joint described in Letters Patent ofthe United States No. 124,011, especially when made of zinc, isobjectionable on account of the liability of the edges of the joint toslip byeach other, the effect of which is to loosen and open the joint,causing the pipe to leak. "A sheet-metal pipe constructed in accordancewith my invention is particularly appli cable for stove-pipes, hot airand water conductors, speaking-tubes, &c., but will be found equallyuseful for many other purposes and this pipe may be made ornamental, ifdesired, by forming it of different kinds of metal of the same or ofdifferent widths, or of a strip of one ,metal with a re-enforcing stripof another metal.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. A spirally-wound sheetmetal pipe in which the seam or joint isre-enforced by a strip of metal, a, clinched down thereon, substantiallyas and for-the purpose described.

2. A spirally-Wound sheet-metal pipe, constructed with a joint formed byturning and abutting the edges of the metal, and uniting or looking themtogether by means of a re-eir forcing-strip, a, substantially as setforth.

Witness my hand this 1st day of December, A. D. 1876.

HENRY NOBLE.

In presence of- N. W. STEARNS, W. J. CAMBRIDGE.

